NASA releases interactive 3D geoid model showing Earth's gravity-driven ocean surface
NASA released an interactive 3D geoid model this month: the ocean surface shaped by gravity alone. 15 years of satellite data show height swinging from +85m near Iceland to -106m off southern India. Every altitude on Earth is measured against this surface. Source: NASA.
NASA's Scientific Visualization Studio has released a new interactive 3D model of the geoid, the surface global oceans would form if shaped purely by Earth's gravity field and rotation, without tides, wind, or currents. The visualization is built on the GOCO06s gravity model, a satellite-only dataset compiled from more than a billion observations gathered over 15 years by 19 satellites, including NASA's GRACE mission and the European Space Agency's GOCE. The results show that gravity height across the planet is far from uniform: it peaks at +85 meters near Iceland and drops to -106 meters off the coast of southern India, a swing of 191 meters that NASA's visualization exaggerates by a factor of 10,000 to make visible. This is not just a scientific curiosity. The geoid is the actual reference surface used to define sea level and altitude everywhere on Earth, from aviation charts to coastal flood maps. Because gravity is uneven, two locations at identical GPS elevation can sit at meaningfully different heights relative to true sea level, a detail that matters for anyone modeling sea level rise, aircraft altitude, or satellite orbit precision. NASA credits the model to visualizer Mark SubbaRao at Goddard Space Flight Center, with the underlying gravity data drawn from a research consortium spanning multiple space agencies. Source: NASA Scientific Visualization Studio.